1. Field of the Invention
The present invention relates to an image recording apparatus which records an image on a recording medium transported by a transport section. In particular, the present invention relates to the setting of the transport amount in relation to the transport section during the recording.
2. Description of the Related Art
Conventionally, an image recording apparatus, which is exemplified, for example, by a printer, a copying machine, and a facsimile, transports a recording medium such that the recording medium is interposed or nipped by a transport roller pair composed of a transport roller which uses a driving motor as a driving source and a driven roller which is arranged opposingly to the transport roller. The recording medium, which is transported by the transport roller pair, is transported to a recording section, and an image is recorded on the recording medium by the recording section.
Incidentally, in recent years, it is demanded for the image recording apparatus that the image is recorded in a higher quality. In order to perform the high quality image recording, it is demanded to improve the transport accuracy of the recording medium transported by the transport roller pair. In view of the above, Japanese Patent Application Laid-open No. 2000-6478 discloses a paper feed control method including measuring, for each of types of recording paper, a relationship between a recording paper feed amount brought about by a transport roller which is pressed by a driven roller and a rotation amount of a driving motor which drives the transport roller, selecting a correction value of the rotation amount of the driving motor for each of the types of the recording paper based on the measured data, and controlling the rotation amount of the driving motor by using the selected correction value. In this way, the transport amount is set differently depending on each of the types of the recording paper.
However, the interposing force or nipping force of the transport roller pair, which is exerted on the recording medium, is not constant in some cases in the direction perpendicular to the transport direction of the transport roller pair. In the case of the paper feed control method described in Japanese Patent Application Laid-open No. 2000-6478, the transport amount is set depending on each of the types of the recording paper, but the transport amount is not set for recordings when the positions differ in the direction perpendicular to the transport direction of the recording papers transported by the transport roller pair. Therefore, the transport accuracy is consequently lowered depending on the positions of the recording mediums in the direction perpendicular to the transport direction. It is impossible to record the image at a high quality in some cases.